Got my bike running and passed the vehicle inspection. Day after I noticed that left front caliper was leaking. I cheaped out when ordering parts. I was thinking about the std caliper piston when order a complete right brake doing dual. "The pistons did not leak last year"
I replaced the o-ring and found rust pits on caliper. Removed that with nail and 1000 grit paper. Leak arrived shortly.
I was lucky to find a NOS brake piston in stock (last one) + seat pad + seal where I bought my bike 1979, 90km from home. Mounted it and now hopefully OK!!
Strange.... bleeding the front brakes still no problems, easy and quickly done when gravitation will do most of the work. This time with dual front calipers. 0.5m hose on bleeder screw that is open, no need of pumping, closing, pumping....... Just open it and let it bleed, slowly press the brake lever. Air bubbles out from the hose soon with fluid only, not letting air in. Refill MC with fluid during the process. Cover tank and other painted areas with a clocth or old clean sheet.
I've read many threads about bleed problems....